3,691 research outputs found
Marginal abatement cost curves for UK agriculture, forestry, land-use and land-use change sector out to 2022
Greenhouse gas emissions from agriculture, land use, land use change and forestry (ALULUCF) are a significant percentage of UK industrial emissions. The UK Government is committed to ambitious targets for reducing emissions and all significant industrial sources are coming under increasing scrutiny. The task of allocating shares of future reductions falls to the newly appointed Committee on Climate Change (CCC), which needs to consider efficient mitigation potential across a range of sectors. Marginal abatement cost curves are derived for a range of mitigation measures in the agriculture and forestry sectors over a range of adoption scenarios and for the years 2012, 2017 and 2022. The results indicate that in 2022 around 6.36 MtCO2e could be abated at negative or zero cost. Further, in same year over 17% of agricultural GHG emissions (7.85MtCO2e) could be abated at a cost of less than the 2022 Shadow Price of Carbon (ÂŁ34tCO2e).Environmental Economics and Policy,
MARGINAL ABATEMENT COST CURVES FOR UK AGRICULTURAL GREENHOUSE GAS EMISSIONS
This paper addresses the challenge of developing a âbottom-upâ marginal abatement cost curve (MACC) for greenhouse gas emissions from UK agriculture. A MACC illustrates the costs of specific crop, soil, and livestock abatement measures against a ââbusiness as usualââ scenario. The results indicate that in 2022 under a specific policy scenario, around 5.38 MtCO2 equivalent (e) could be abated at negative or zero cost. A further 17% of agricultural GHG emissions (7.85 MtCO2e) could be abated at a lower unit cost than the UK Governmentâs 2022 shadow price of carbon (ÂŁ34 (tCO2e)-1). The paper discusses a range of methodological hurdles that complicate cost-effectiveness appraisal of abatement in agriculture relative to other sectors.Climate change, Marginal abatement costs, Agriculture, Environmental Economics and Policy, Resource /Energy Economics and Policy, Q52, Q 54, Q58,
An EPID-based method for comprehensive verification of gantry, EPID and the MLC carriage positional accuracy in Varian linacs during arc treatments
BACKGROUND: In modern radiotherapy, it is crucial to monitor the performance of all linac components including gantry, collimation system and electronic portal imaging device (EPID) during arc deliveries. In this study, a simple EPID-based measurement method has been introduced in conjunction with an algorithm to investigate the stability of these systems during arc treatments with the aim of ensuring the accuracy of linac mechanical performance. METHODS: The Varian EPID sag, gantry sag, changes in source-to-detector distance (SDD), EPID and collimator skewness, EPID tilt, and the sag in MLC carriages as a result of linac rotation were separately investigated by acquisition of EPID images of a simple phantom comprised of 5 ball-bearings during arc delivery. A fast and robust software package was developed for automated analysis of image data. Twelve Varian linacs of different models were investigated. RESULTS: The average EPID sag was within 1Â mm for all tested linacs. All machines showed less than 1Â mm gantry sag. Changes in SDD values were within 1.7Â mm except for three linacs of one centre which were within 9Â mm. Values of EPID skewness and tilt were negligible in all tested linacs. The maximum sag in MLC leaf bank assemblies was around 1Â mm. The EPID sag showed a considerable improvement in TrueBeam linacs. CONCLUSION: The methodology and software developed in this study provide a simple tool for effective investigation of the behaviour of linac components with gantry rotation. It is reproducible and accurate and can be easily performed as a routine test in clinics
Standards in Neurological Rehabilitation, June 1997
The last decade has been a remarkable one for statutory interpretation. For most of our history, American judges have been pragmatists when it comes to interpreting statutes. They have drawn on various conventions â the plain meaning rule, legislative history, considerations of statutory purpose, canons of construction â much as a golfer selects the proper club when he gauges the distance to the pin and the contours of the course. The arrival of Justice Scalia on the Supreme Court has changed this. Justice Scalia is a foundationalist, insisting that certain interpretational tools should be permanently banned from judicial use. What is more, Justice Scalia is sufficiently committed to his views about legal method that he often declines to join other Justice\u27s opinions that employ improper methods. This unyielding stance, reinforced by the appointment of Justice Thomas, who appears to share similar convictions, is producing a major transformation in the way the Supreme Court approaches a statutory interpretation cases
GPU accelerated biochemical network simulation
Motivation: Mathematical modelling is central to systems and synthetic biology. Using simulations to calculate statistics or to explore parameter space is a common means for analysing these models and can be computationally intensive. However, in many cases, the simulations are easily parallelizable. Graphics processing units (GPUs) are capable of efficiently running highly parallel programs and outperform CPUs in terms of raw computing power. Despite their computational advantages, their adoption by the systems biology community is relatively slow, since differences in hardware architecture between GPUs and CPUs complicate the porting of existing code
GPU accelerated biochemical network simulation
Motivation: Mathematical modelling is central to systems and synthetic biology. Using simulations to calculate statistics or to explore parameter space is a common means for analysing these models and can be computationally intensive. However, in many cases, the simulations are easily parallelizable. Graphics processing units (GPUs) are capable of efficiently running highly parallel programs and outperform CPUs in terms of raw computing power. Despite their computational advantages, their adoption by the systems biology community is relatively slow, since differences in hardware architecture between GPUs and CPUs complicate the porting of existing code
Autonomous three dimensional Newtonian systems which admit Lie and Noether point symmetries
We determine the autonomous three dimensional Newtonian systems which admit
Lie point symmetries and the three dimensional autonomous Newtonian Hamiltonian
systems, which admit Noether point symmetries. We apply the results in order to
determine the two dimensional Hamiltonian dynamical systems which move in a
space of constant non-vanishing curvature and are integrable via Noether point
symmetries. The derivation of the results is geometric and can be extended
naturally to higher dimensions.Comment: Accepted for publication in Journal of Physics A: Math. and Theor.,13
page
Glueball Spectroscopy in a Relativistic Many-Body Approach to Hadron Structure
A comprehensive, relativistic many-body approach to hadron structure is
advanced based on the Coulomb gauge QCD Hamiltonian. Our method incorporates
standard many-body techniques which render the approximations amenable to
systematic improvement. Using BCS variational methods, dynamic chiral symmetry
breaking naturally emerges and both quarks and gluons acquire constituent
masses. Gluonia are studied both in the valence and in the collective, random
phase approximations. Using representative values for the strong coupling
constant and string tension, calculated quenched glueball masses are found to
be in remarkable agreement with lattice gauge theory.Comment: 12 pages, 1 uuencoded ps figure, RevTe
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